• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 2 answers
  • Subscribers 83 subscribers
  • Views 276 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LAUNCHXL-F28069M: BOOSTXL-DRV8301 LAB2B RoverL get a negative value

Cherry Zhou
Mastermind 22235 points
Part Number: LAUNCHXL-F28069M

Hi Team,

a PMSM motor with parameter:

pole pairs = 10

rate speed = 180RPM

rate voltage = 36V

Rs = 5.0R

Stator inductance = 27mH

Time constance = L/R = 5.4mS

The customer use lab02b to test the RoverL and Rs，

RoverL = -7415   not correct

Rs = 4.9R

power voltage = 20 -24VDC

Test codition set as followed

#define USER_IQ_FULL_SCALE_FREQ_Hz               (300.0) 
#define USER_IQ_FULL_SCALE_VOLTAGE_V          (24.0) // 24.0 Example for boostxldrv8301_revB typical usage and the Anaheim motor
#define USER_ADC_FULL_SCALE_VOLTAGE_V       (26.314)      // 26.314 boostxldrv8301_revB voltage scaling

#define USER_IQ_FULL_SCALE_CURRENT_A (20.0) // 20.0 Example for boostxldrv8301_revB typical usage

#define USER_ADC_FULL_SCALE_CURRENT_A (33.0) // 33.0 boostxldrv8301_revB current scaling

#define USER_MOTOR_NUM_POLE_PAIRS (10)
#define USER_MOTOR_Rr (NULL)
#define USER_MOTOR_Rs (NULL)
#define USER_MOTOR_Ls_d (NULL)
#define USER_MOTOR_Ls_q (NULL)
#define USER_MOTOR_RATED_FLUX (NULL)
#define USER_MOTOR_MAGNETIZING_CURRENT (NULL)
#define USER_MOTOR_RES_EST_CURRENT (1.0)
#define USER_MOTOR_IND_EST_CURRENT (-0.5)
#define USER_MOTOR_MAX_CURRENT (2.0)
#define USER_MOTOR_FLUX_EST_FREQ_Hz (20.0)

Changing power supply to 12V, the RoverL value still -7900. Why the RoverL value is a negative value causing the Ls test is not able to be finished? 

#define USER_PWM_FREQ_kHz (20.0) //30.0 Example, 8.0 - 30.0 KHz typical; 45-80 KHz may be required for very low inductance, high speed motors

#define USER_R_OVER_L_EST_FREQ_Hz (100)               // 300 Default

#define USER_VOLTAGE_FILTER_POLE_Hz  (364.682)   // 364.682, value for boostxldrv8301_revB hardware

Parameters below is being set to check the hardware and LAB02b got the right value:

pole pairs = 4

rate speed = 3000RPM

rate voltage = 24V

Rs = 1.02R

Stator inductance = 0.59mH

It can be confirmed the hardware is ok and all the procedure has no fault.

Could you help check this case? Thanks.

Best Regards,

Cherry

  • 0
    TI__Guru** 112290 points

    Are you using the TI EVM kits? Or the customize board?

    Did you apply the enough DC bis for this motor?

    Did you try to run the lab01v and lab01c to verify the board?

    Don't add any load to the motor for running the lab02b for identification.

  • 0 in reply to Yanming Luo
    TI__Mastermind 22235 points

    Hi Yanming,

    Thank you for the support.

    Yes, they do use the TI origin launchpad and boostxl board. 

    And they do use another motor as listed to check the board and get the right value, the bias was set by the hardware to get read the correct value.

    The customer is wondering the reason why the motor identify prog work not correct at the pmsm low speed motor and why they got a negative value.

    Thanks and regards,

    Cherry

  • 0 in reply to Cherry Zhou
    TI__Guru** 112290 points

    Try to run the lab02c if the motor is a low inductance motor. And please don't add any load on the motor for identification, and set the correct identification variables value in the file of user.h according to the specification of the motor, to make sure the motor spin smoothly during Flux measurement and Ls identification states.

    #define USER_MOTOR_RES_EST_CURRENT     (2.0)                               // A - 10-30% of rated current of the motor

    #define USER_MOTOR_IND_EST_CURRENT     (-1.5)                             // A - 10-30% of rated current of the motor, just enough to enable rotation

    #define USER_MOTOR_MAX_CURRENT           (20.0)                               // A - 30~150% of rated current of the motor

    #define USER_MOTOR_FLUX_EST_FREQ_Hz     (40.0)                           // Hz - 10~30% rated frequency of the motor

  • 0 in reply to Yanming Luo
    Prodigy 10 points

    Thanks a lot.

    #define USER_MOTOR_RES_EST_CURRENT     (2.0)                               // A - 10-30% of rated current of the motor

    #define USER_MOTOR_IND_EST_CURRENT     (-1.5)                             // A - 10-30% of rated current of the motor, just enough to enable rotation

    After change the two parameter, successfully completed the motor parameter identification process.